Shaykh Ibn ‘Uthaymeen said:
The one who hastens in praying quickly – at a pace void of being calm and at ease, then his prayer is invalid; [whether that is] the obligatory [prayer] or the voluntary [prayer].
That is because a man came to the masjid and prayed without being calm and at ease, so the Prophet ﷺ said to him:
«Go back and pray [again], for you have not prayed.» – [saying this to him] three times. [al-Bukhaaree, no.757]
So being calm and at ease [in prayer] is imperative; and how strange of the children of Aadam, and the haste of the children of Aadam, and the ignorance of the children of Aadam, and the injustice of the children of Aadam!
How he hastens at this fast pace while addressing Allaah and calling upon Him?!
If a person stood with his friend – talking to him, he would remain for an hour or [even] two standing, without [tiring or] getting bored.
So how is it [when] he is standing before Allaah (’Azza wa Jall) – calling upon Him and addressing Him, [saying] ‘O Lord’, ‘Lord forgive me’, ‘Glory be to my Lord the Most High’, ‘Glory be to my Lord the Great’ – calling upon Him with these words?
How [then] does he hasten his pace [in prayer]?
Is there an army [of foes] behind him?!!
Of course not!
But Shaytaan is [indeed] our enemy, and by Allaah, he does not wish anything for us except that which is evil for us.
He loves to deter us from the remembrance of Allaah, and from the prayer, and [whispers to us] saying: ‘Come on!, hurry!, hurry!, quickly!’ – as if we are upon burning embers!
And [so] I say O my brother, try be calm and at ease in prayer; call to mind, as if you are addressing Allaah and calling upon Him.
[Do this] until you experience its taste, and until it becomes the apple of your eye – just as it was the apple of the eye of the Messenger of Allaah ﷺ.
Accustom yourself to this [approach in prayer], and you will [grow to] love it, and when the prayer finishes, you will say ‘OK, bring on the next prayer’.
As for stealing it [in the manner described earlier], then this is theft from Shaytaan, [and] we seek refuge in Allaah from Shaytaan the accursed; O Allaah protect us all from Shaytaan the accursed.